The instant invention is directed to an information reader for reading light transmissive or light reflective information from an information carrying medium, and in particular to a card reader utilizing the same light sensitive circuitry for detecting light reflected off of a card and light transmitted through openings in a card.
Heretofore, card readers capable of reading both reflective information from a card and transmissive information passed through the openings of a card have been characterized by the use of a single light source disposed on a first side of the card to be read, and two columns of light sensitive transducers. The first column of light sensitive transducers is utilized to detect the presence or absence of light reflected from the card and the second column of transducers is utilized to detect the presence or absence of light transmitted through the card. The respective photodetectors in each column of light sensitive transducers are coupled through a two position switch to an output amplifier, thereby requiring a two contact switch for each column of information to be read, thereby complicating the coupling of the output amplifier circuits to the respective photodetectors, and additionally, preventing the miniaturization and simplification of the card reader. Accordingly, a card reader eliminating the aforementioned disadvantages is hereinafter described.